Binary phase shift keying modulation system and/or frequency multiplier

ABSTRACT

A low cost spread spectrum modulator for BPSK, or Binary Phase Shift Keying capable of outputting the high modulation rate and suppressed carrier output needed in spread spectrum systems. The present invention provides high quality BPSK modulation without the double balance mixers as required in the prior art, thereby dispensing with the necessity of complex transistor/potonciometer or diode/transformer arrangements. The present invention provides BPSK modulation utilizing only one transformer, which can be adjusted for carrier suppression and two transistors. FET&#39;s, or digital logic gates or the like, allowing the present system to be driven from low power CMOS logic levels, yet producing eight db of gain. The present invention may also be utilized as a frequency multiplier, with the utilization of the appropriately high frequency transistor, FET, digital logic gate, or the like.

REFERENCE TO RELATED APPLICATION

The present application is a continuation-in-part of patent applicationSer. No. 07/572,468 filed Aug. 27, 1990, now U.S. Pat. No. 5,119,396,issued Jun. 2, 1992.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to modulators, and more particularly to animproved spread spectrum BPSK, or Binary Phase Shift Keying, Modulationsystem designed for providing gain, low cost and suppressed carrieroutput, as well as compatibility with CMOS low power logic modulationdrive circuitry. The present invention also teaches a FrequencyMultiplier circuit, which is much less costly than traditional designscurrently known.

The present system teaches a new, superior, and less costly BPSKmodulator and/or frequency multiplier than that contemplated by theprior art, providing a less complicated system while outputtingincreased gain over prior art modulators.

2. Prior Art & General Background

Previous spread spectrum BPSK modulators required conventional balancemixers to produce carrier suppression. These conventional modulatorsutilized either 1) a complex transistor array in conjunction with atransformer tunable with a potonciometer or 2) two center tappedtransformers and four diodes, which arrangement required a high leveldrive circuit to modulate it, typically +7 to +15 dBM.

Besides the greater expense, increased complexity thereby contributingthe probability of failure, and incompatibility with low power -10 dBCMOS logic drive circuitry, the prior art modulators typically producedon the order of six dB of signal loss, resulting in considerably lesssatisfactory overall performance when compared to the present invention.

3. General, Summary Discussion of the Invention

A low cost spread spectrum modulator is an essential component of acommercially viable spread spectrum communications system. While a lowcost, high performance modulator has not been contemplated until now,the present invention describes the ideal modulator, designedspecifically for Binary Phase Shift Keying or BPSK.

The present invention is designed to provide a low cost, efficient,quality and reliable modulation system having sufficiently high BPSKmodulation rate, coupled with the suppressed carrier output needed inspread spectrum communication systems and the like.

Unlike the prior art, which required balance mixers of the sortdiscussed in the background section supra, the present inventionprovides a BPSK modulator utilizing only one transformer having thecapability of adjusting for maximum carrier suppression, in conjunctionwith two bipolar transistors, which allows the modulator to be drivenfrom the low power logic levels found in CMOS circuitry -10 dBM. Thepresent invention in its preferred embodiment produces eight dB of gain,much superior in performance over the prior art, which performs at a sixdB signal loss.

Further, the preset invention is not limited to utilizing two bipolartransistors as discussed supra and may utilize in an equivalent fashionany device which provides sufficient gain at the desired frequency oroperation, as well as having sufficiently fast switching capabilities.

For example, other acceptable, equivalent devices which may be utilizedin place of the two transistors in the present invention may includehigh frequency field effect transistors (FET's), or digital logic gates,which are biased into a linear region utilizing common techniques. Thesedevices may be incorporated into the system of the present invention,replacing in effect the transistors, utilizing common engineeringtechniques.

The present invention, in an alternative use, may be utilized as afrequency multiplier. For example, if the transistor, or its equivalent,is adequately fast, for example, F_(t) >1 GHZ, the system may beutilized to create at its output a higher frequency harmonic.

As is known in the art, it is a common radio design practice to utilizea non-linear device such as a diode, transistor, or the like to performfrequency multiplication. This is desirable because only lower frequencycrystals are readily available, and as such, the lower frequency mustthen be translated into the higher, desired frequency.

When the modulation transistor arrangement is additionally utilized inthe present invention in the frequency modulation capacity, lesssubsequent stages are required. This serves to lower both the cost andcomplexity of a frequency multiplier system, when compared to the priorart systems.

It is thus an object of the present invention to provide a low cost,high quality BPSK modulator compatible for use in spread spectrum-typecommunications systems.

It is another object of the present invention to provide a BPSKmodulation system which is compatible with low power logic input, suchas that driven by CMOS circuitry.

It is still another object of the present invention to provide a BPSKmodulator which utilizes a single transformer and two transistors,adjusts for carrier suppression, and provides eight db+ of gain.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects of the presentinvention, reference should be had to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like parts are given like reference numerals, and wherein:

FIG. 1 is a Schematic Illustration of the preferred embodiment of theBPSK Modulator of the present invention;

FIG. 2 is Schematic Illustration of an alternative, less costlyembodiment of the BPSK Modulator of FIG. 1.

FIG. 3 is a Schematic Illustration of an alternative embodiment of theBPSK Modulator having transistors precede a phase shifting transformer;and

FIG. 4 is a Schematic Illustration of an alternative embodiment of theBPSK Modulator replacing transistors with very high speed logic gates.

DESCRIPTION OF THE PREFERRED EXEMPLARY EMBODIMENT(S)

The described modulator uses only one transformer which also adjusts forcarrier suppression and two transistors, and as such can be driven fromlow power CMOS logic levels producing a full eight dB of gain.

BPSK modulation seeks to alternate a carrier between a 0 degree phaseshift and a 180 degree phase shift, the phase shift of the carrierproviding the modulation. As illustrated in FIG. 1 of the presentinvention, the outputs of the transformer "A", when the center tap "B"is grounded, are inherently at opposite phases, 0 degrees and 180degrees.

Transistor C and D can then be alternately selected by biasing the MOD +or MOD - inputs to on. Thus, either the 0 degree phase shift or 180degree phase shift can be selected, which provides BPSK modulation with8 dB of gain.

An alternative embodiment to the present invention obviates with theneed for the costly center tap in the transformer, further simplifyingthe present design. This circuit is based upon the premise that aninductor at resonance has outputs 180 degrees out of phase, producing 0and 180 degrees outputs. The 0 degree and 180 degree outputs areselected using the same MOD -, MOD + biasing as described above.

Through extensive experimentation, the present inventor has determinedthat either tight (>0.6 coupling coefficient) or loose (<0.3 couplingcoefficient) coupling of the transformer windings can be used to productsuitable 0 degree and 180 degree phase shifts for BPSK modulation.

As illustrated in FIG. 2, in the embodiment implementing the looselycoupled transformer, both capacitors G and F must be configured toresonate in conjunction with the carrier frequency to be modulated. Theresonate point in this circuit may be fine adjusted by varying thetransformer's inductance, by turning the tunable core or slug oftransformer E.

In a tightly coupled transformer, capacitor G can be eliminated andtransformer E must be only resonate with capacitor F. Fine tuning isagain achieved by adjusting the slug or core of transformer E. The valueof capacitor F must be such that it resonates with transformer E at thefrequency to be modulated.

Both embodiments of the invention perform identically when properlyconfigured and can produce excellent BPSK spread spectrum modulationwith adjustable carrier suppression.

As discussed above, the value of the resonate capacitors to befrequency. In the present invention, if a 11/2 primary turn to 2 1/2secondary turn transformer is used with a carrier frequency of 300 MHz,then practical resonate capacitor values are 2.2 to 6.8 pf for G & E.The series coupling capacitors must be relatively small to minimizecoupling of transistor base to collector capacitance. Practical valuesare from 2.2 to 8.2 pf.

The transformer turns ratio is selected to match the impedance of thedriving carrier CKT to the input impedance of the gain/phase selectiontransistors.

Since FIG. 2 must be in resonance to function, the overall Q of the CKTand transformer coupling can be chosen to optimize performance as atuned filter. Q is primarily effected by the transformer slug loss.Further loosely coupled transformers provide optimum filteringcharacteristics. This function can filter out undesirable harmonics fromprevious RF stages, eliminating otherwise required additional filtercomponents.

The overall 8 dB of gain realized is a product of sums of both gain andlosses of the entire circuit. The transformer produces 2 to 4 dB ofloss, the coupling capacitors produce 1 dB of loss, the transistorsprovide 12 to 13 dB of gain. The average circuit gain is determined asthe minimum overall gain (12-4-1)=7 dB to a maximum overall gain of(13-2-1)=10 dB of gain.

As discussed infra, the present invention's design is not limited to usein BPSK modulation. The present invention, in an alternative use, may beutilized as a frequency multiplier.

For example, if the transistor(s), or their equivalents, as utilized inthe present invention, is adequately fast, for example. F_(t) >1 GHZ,the system may be utilized to create at its output a higher frequencyharmonic. The circuit layout, and implementation of this alternativeembodiment would remain substantively the same as set forth in thefigures shown.

As is known in the art, it is a common radio design practice to utilizea non-linear device such as a diode, transistor, or the like to performfrequency multiplication. This is desirable because only lower frequencycrystals are readily available, and as such, the lower frequency mustthen be translated into the higher, desired frequency.

When the modulation transistor arrangement is additionally utilized inthe present invention in the frequency modulation capacity, lesssubsequent stages are required. This serves to lower both the cost andcomplexity of a frequency multiplier system, when compared to the priorart systems.

The embodiment(s) described herein in detail for exemplary purposes areof course subject to many different variations in structure, design,application and methodology. Because many varying and differentembodiments may be made within the scope of the inventive concept(s)herein taught, and because many modifications may be made in theembodiment(s) herein detailed in accordance with the descriptiverequirements of the law, it is to be understood that the details hereinto be interpreted as illustrative and not in a limiting sense.

As a further example, other acceptable, equivalent devices may beutilized in place of the two transistors in the present invention. Thesemay include high frequency field effect transistors (FET's), or digitallogic gates, which are biased into a linear region utilizing commontechniques. These devices may be incorporated into the system of thepresent invention, replacing in effect the transistors, utilizing commonengineering techniques.

For example, the topological dual of the described circuits is alsopracticable, having the gain or frequency multiplication precede thephase shifting transformer. In an alternate embodiment of the presentinvention, as shown in FIG. 3, a frequency f_(IN) is introduced at 501,so that the frequency f_(IN) is AC coupled and present on bothtransistors 502 and 503. BPSK data is generated in complement viainverter 508, thereby selecting, via base bias resistors, transistors502 or 503. The collectors are connected via the opposite center tappedprimary windings of transformer 506. The center tap provides DC powerand AC bypass. The selection of transistor 502 or 503 thereby forces a0° or 180° phase relationship on f_(OUT) 509. Capacitors 504, 505, and507 can be used to effect single or double pole filtering depending onthe coupling of transformer 506. Frequency multiplication can also beachieved with transistors 502 and 503 by adjusting bias and drive levelsfor nonlinear output, as well as tuning transformer 506 to the targetharmonic.

An additional alternate embodiment of the present invention, illustratedin FIG. 4, has very high speed logic gates 403, 405 biased into a linearregion and replacing transistors 502, 503 of FIG. 3. As shown in FIG. 4,a frequency is introduced via f_(IN) in 401. Bias network means,embodied as a DC bias device 402, is used to force logic elements 403,405 into a linear region of operation. Either AND gates or OR gates canbe made to function in this circuit. The inverter 404 providescomplementary BPSK data thereby selecting either gate 403 or gate 405.The outputs then drive the primary of a transformer 407 causing either a0° or a 180° phase shift on the output of the transformer 407 at f_(OUT)409. In addition, the transformer 407 can be used as a one or two polefilter in conjunction with capacitors 406, 408, depending on thecoupling coefficient of the transformer 407.

Furthermore, gates 403, 405 can be used as frequency multipliers byadjusting the DC offset and drive levels on the inputs of gates 403,405, and tuning transformer 407 to the desired harmonic output.

What is claimed is:
 1. A BPSK Modulator circuit, comprising:atransformer, said transformer further comprising first induction meanshaving a carrier input leg and an output leg, second induction meanshaving first and second leg outputs, said transformer configured suchthat said first and second leg outputs of said second induction meansmodulates at opposite phases of 180 and 0 degrees, forming "MOD +" and"MOD -", respectively, relative a carrier signal supplied to saidcarrier input of said first induction means; first and second phaseselection means configured to modulate via input of said of said firstand second outputs of said second induction means, said first and secondphase selection means further comprising first and second loadtransistors or their equivalent, respectively, each having an emitter,and a base or the equivalent, said base of said first transistor incircuit with said first output of said second inductor, receiving said"MOD +", said base of said second transistor in circuit with said secondoutput of said second inductor, receiving said "MOD -".
 2. A BPSKModulator circuit having a tunable slug or core to adjust carriersuppression in a spread spectrum system, comprising:a transformer, saidtransformer further comprising first induction means having a carrierinput leg and an output leg, second induction means having first andsecond leg outputs, and a tunable slug or core in communication withsaid first and second induction means, said transformer configured suchthat said first and second leg outputs of said second induction meansmodulates at opposite phases of 180 and 0 degrees, forming "MOD +" and"MOD -", respectively, relative a carrier signal supplied to saidcarrier input of said first induction means; first and second phaseselection means configured to modulate via input of said first andsecond leg outputs of said second induction means, said first and secondphase selection means further comprising first and second loadtransistors, respectively, each having an emitter, a collector, and abase, said base of said first transistor in circuit with said firstoutput leg of said second inductor, receiving said "MOD +", said base ofsaid second transistor in circuit with said second output leg of saidsecond inductor, receiving said "MOD -".
 3. A BPSK Modulator circuitutilizing a loosely coupled transformer to adjust carrier suppression ina spread spectrum system, comprising:a transformer, said transformerfurther comprising first induction means having a carrier input leg andan output leg, second induction means loosely coupled with said firstinduction means, said second induction means having first and second legoutput, said transformer configured such that said first and second legoutputs of said second induction means modulates at opposite phases of180 and 0 degrees, forming "MOD +" and "MOD -", respectively, relative acarrier signal supplied to said carrier input of said first inductionmeans; first and second capacitors, said first capacitor in parallelcircuit with said carrier input leg and grounded output leg of saidfirst induction means, said second capacitor in parallel circuit withsaid first and second leg outputs of said second induction means, firstand second phase selection means configured to modulate via input ofsaid first and second outputs of said second induction means, said firstand second phase selection means further comprising first and secondload transistors, respectively, each having an emitter, a collector, anda base, said base of said first transistor in serial circuit with saidfirst leg output of said second inductor, receiving said "MOD +", saidbase of said second transistor in serial circuit with said second legoutput of said second inductor, receiving said "MOD -".
 4. The BPSKModulation System of claim 3, wherein there is further included atunable slug or core is in communication with said first and secondinductors.
 5. The BPSK Modulation System of claim 4, wherein there isfurther included resonator capacitor means in parallel circuit with saidfirst and said second leg outputs of said second induction means, saidresonator capacitor transformer coupling means configured to provideband pass filtering for previous stage harmonic suppression.
 6. A BPSKModulator circuit having a tightly coupled transformer having no centertap and a single parallel resonate capacitor on the secondary to provideBPSK modulation, comprising:a transformer, said transformer furthercomprising first induction means having a carrier input leg and anoutput leg, second induction means tightly coupled to said firstinduction means, said second induction means having first and second legoutputs, said transformer configured such that said first and second legoutputs of said second induction means modulates at opposite phases of180 and 0 degrees, forming "MOD +" and "MOD -", respectively, relative acarrier signal supplied to said carrier input of said first inductionmeans; band pass filter means for filtering harmonic suppression fromsaid transformer, said band pass filter means further comprising aresonate capacitor in parallel circuit with said first and second legoutputs of said second induction means; first and second phase selectionmeans configured to modulate via input of said of said first and secondoutputs of said second induction means, said first and second phaseselection means further comprising first and second load transistors,respectively, each having an emitter, a collector, and a base, said baseof said first transistor in circuit with said first leg output of saidsecond inductor, receiving said "MOD +", said base of said secondtransistor in circuit with said second output of said second inductor,receiving said "MOD -".
 7. The BPSK Modulation System of claim 6,wherein said system further comprises adjustment means for adjustingcarrier suppression, said adjustment means further comprising a tunableslug or core in communication with said first and second inductionmeans.
 8. The BPSK Modulation System of claim 6, wherein there isfurther included resonator capacitor means in parallel circuit with saidfirst and said second leg outputs of said second induction means, saidresonator capacitor means configured to provide band pass filtering forprevious stage harmonic suppression. . .9. A frequency multipliercircuit, comprising:a transformer, said transformer further comprisingfirst induction means having a carrier input leg and an output leg,second induction means having first and second leg outputs, saidtransformer configured such that said first and second leg outputs ofsaid second induction means modulates at opposite phases of 180 and 0degrees, forming "MOD +" and "MOD -", respectively, relative a carriersignal supplied to said carrier input of said first induction means;phase selection means configured to modulate via input of said of saidfirst and second outputs of said second induction means, said phaseselection means having a F_(t) >1 GHZ, and further comprising anemitter, and first and second bases or the equivalent, said first basein circuit with said first output of said second inductor, receivingsaid "MOD +", said second base in circuit with said second output orsaid second inductor, receiving said "MOD -"..!.. .10. A frequencymultiplier circuit, comprising: a transformer, said transformer furthercomprising first induction means having a carrier input leg and anoutput leg, second induction means having first and second leg outputs,said transformer configured such that said first and second leg outputsof said second induction means modulates at opposite phases of 180 and 0degrees, forming "MOD +" and "MOD -", respectively, relative a carriersignal supplied to said carrier input of said first induction means;phase selection means configured to modulate via input of said of saidfirst and second outputs of said second induction means, said phaseselection means having a F_(t) >1 GHZ, and further comprising anemitter, and first and second bases or the equivalent, said first basein circuit with said first output of said second inductor, receivingsaid "MOD +", said second base in circuit with said second output ofsaid second inductor, receiving said "MOD -"..!.11. A frequencymultiplier circuit utilizing a loosely coupled transformer to adjustcarrier suppression, comprising:a transformer, said transformer furthercomprising first induction means having a carrier input leg and anoutput leg, second induction means loosely coupled with said firstinduction means, said second induction means having first and second legoutput, said transformer configured such that said first and second legoutputs of said second induction means modulates at opposite phases of180 and 0 degrees, forming "MOD +" and "MOD -", respectively, relative acarrier signal supplied to said carrier input of said first inductionmeans; first and second capacitors, said first capacitor in parallelcircuit with said carrier input leg and grounded output leg of saidfirst induction means, said second capacitor in parallel circuit withsaid first and second leg outputs of said second induction means, phasesection means configured to modulate via input of said of said first andsecond outputs of said second induction means, said phase selectionmeans having a F_(t) >1 GHZ, and further comprising an emitter, andfirst and second bases or the equivalent, said first base in circuitwith said first output of said second inductor, receiving said "MOD +",said second base in circuit with said second output of said secondinductor, receiving said "MOD -".
 12. The method of modulating a carrierbetween a 0 degree phase shift and a 180 degree phase shift, comprisingthe following steps:a. providing a transformer, said transformer furthercomprising first induction means having a carrier input leg and anoutput leg, and second induction means having first and second legoutputs, and a tunable slug or core in communication with said first andsecond induction means; b. tuning said slug or core such that said firstand second leg outputs of said second induction means modulates atopposite phases of 180 and 0 degrees, forming "MOD +" and "MOD -",respectively, relative a carrier signal supplied to said carrier inputof said first induction means; c. providing first and second phaseselection means configured to modulate via input of said first andsecond leg outputs of said second induction means, said first and secondphase selection means further comprising first and second loadtransistors, respectively, each having an emitter, a collector, and abase; d. configuring said base of said first transistor in circuit withsaid first output leg of said second inductor, receiving said "MOD +",said base of said second transistor in circuit with said second outputleg of said second inductor, receiving said "MOD -".
 13. The method ofutilizing a loosely coupled transformer to adjust carrier suppression,modulating a carrier signal between a 0 degree phase shift and a 180degree phase shift, comprising the following steps:a. providing atransformer, said transformer further comprising an inductor havingfirst induction means having a carrier input leg, an output leg, andwindings, and second induction means having first and second leg outputsand windings; b. coupling said windings of said first and secondinduction means to a >0.6 and <0.3 coupling coefficient; c. modulatingsaid inductor at opposite phases of 180 and 0 degrees, forming "MOD +"and "MOD -", respectively, relative a carrier signal supplied to saidcarrier input of said first induction means; d. providing first andsecond phase selection means configured to modulate via input of saidfirst and second leg outputs of said second induction means, said firstand second phase selection means further comprising first and secondload transistors, respectively, each having an emitter, a collector, anda base; e. configuring said base of said first transistor in circuitwith said first output leg of said second inductor, receiving said "MOD+", said base of said second transistor in circuit with said secondoutput leg of said second inductor, receiving said "MOD -".
 14. Themethod of claim 13, wherein there is included the further step ofproviding first and second capacitors, said first capacitor in parallelcircuit with said carrier input leg and grounded output leg of saidfirst induction means, said second capacitor in parallel circuit withsaid first and second leg outputs of said second induction means. . .15.The method of multiplying a carrier to provide a higher frequencyharmonic, comprising the following steps:a. providing a transformer,said transformer further comprising first induction means having acarrier input leg and an output leg, and second induction means havingfirst and second leg outputs, and a tunable slug or core incommunication with said first and second induction means; b. tuning saidslug or core such that said first and second leg outputs of said secondinduction means modulates at opposite phases of 180 and 0 degrees,forming "MOD +" and "MOD -", respectively, relative a carrier signalsupplied to said carrier input of said first induction means; c.providing phase selection means configured to modulate via input of saidof said first and second outputs of said second induction means, saidphase selection means having a F_(t) >1 GHZ, and further comprising anemitter, and first and second bases or the equivalent, said first basein circuit with said first output of said second inductor, receivingsaid "MOD +", said second base in circuit with said second output ofsaid second inductor, receiving said "MOD -", d. configuring said firstbase in circuit with said first output leg of said second inductor,receiving said "MOD +", and said second base in circuit with said secondoutput leg of said second inductor, receiving said "MOD -", multiplyingthe carrier to provide a higher frequency harmonic..!.. .16. The methodof utilizing a loosely coupled transformer to adjust carriersuppression, modulating a carrier signal between a 0 degree phase shiftand a 180 degree phase shift, and multiplying a carrier to provide ahigher frequency harmonic, comprising the following steps: a. providinga transformer, said transformer further comprising an inductor havingfirst induction means having a carrier input leg, an output leg, andwindings, and second induction means having first and second leg outputsand windings; b. coupling said windings of said first and secondinduction means to a >0.6 and <0.3 coupling coefficient; c. modulatingsaid inductor at opposite phases of 180 and 0 degrees, forming "MOD +"and "MOD -", respectively, relative a carrier signal supplied to saidcarrier input of said first induction means; d. providing phaseselection means configured to modulate via input of said of said firstand second outputs of said second induction means, said phase selectionmeans having a F_(t) >1 GHZ, and further comprising an emitter, andfirst and second bases or the equivalent, said first base in circuitwith said first output of said second inductor, receiving said "MOD +",said second base in circuit with said second output of said secondinductor, receiving said "MOD -". e. configuring said first base incircuit with said first output leg of said second inductor, receivingsaid "MOD +", and said second base in circuit with said second outputleg of said second inductor, receiving said "MOD -", multiplying thecarrier to provide a higher frequency harmonic..!.17. The method ofclaim . .16.!. .Iadd.28.Iaddend., wherein there is included the furtherstep of providing first and second capacitors, said first capacitor inparallel circuit with said carrier input leg and grounded output leg ofsaid first induction means, said second capacitor in parallel circuitwith said first and second leg outputs of said second induction means.18. A BPSK modulator comprising:a center tapped transformer having firstand second primary legs, said center tapped transformer having asecondary; amplification means coupled to both first and second primarylegs of said center tapped transformer; selection means, coupled throughsaid amplification means to said center tapped transformer, saidselection means driven by a BPSK data input, for enabling one of thefirst and second primary legs of said center tapped transformer; andcoupling means attached to said secondary of said center tappedtransformer to yield BPSK carrier modulation.
 19. The BPSK modulator asset forth in claim 18, wherein said center tapped transformer is turnedto a resonance frequency by at least one capacitor, thereby providinglow cost filtering.
 0. The BPSK modulator as set forth in claim 18,wherein said amplification means provides frequency multiplication. 21.A BPSK modulator comprising:a plurality of logic gates, each logic gatecoupled to a primary leg of a transformer, to provide amplification;selection means, responsive to a BPSK data input, to enable one of saidplurality of logic gates; and coupling means to yield a BPSK modulatingcarrier signal on a secondary of the transformer.
 22. The BPSK modulatoras set forth in claim 21 wherein the transformer is tuned to a resonancefrequency by a plurality of capacitors, thereby providing low costfiltering.
 23. The BPSK modulator as set forth in claim 21 wherein eachof said plurality of logic gates provides frequency multiplication. 24.A frequency multiplier circuit, comprising:a transformer, saidtransformer further comprising first induction means having a carrierinput leg and an output leg, second induction means having first andsecond leg outputs, said transformer configured such that said first andsecond leg outputs of said second induction means modulate at oppositephases of 180 degrees and 0 degrees, forming "MOD +" and "MOD -",respectively, relative to a carrier signal supplied to said carrierinput of said first induction means; and phase selection meansconfigured to modulate via input of said first and second outputs ofsaid second induction means, said phase selection means having aF_(t) >1 GHz, and further comprising an emitter, and first and secondbases or the equivalent, said first base in circuit with said first legoutput of said second induction means, receiving said "MOD +", saidsecond base in circuit with said second leg output of said secondinduction means, receiving said "MOD -". . .25. A frequency multipliercircuit, comprising: a transformer, said transformer further comprisingfirst induction means having a carrier input leg and an output leg,second induction means having first and second leg outputs, saidtransformer configured such that said first and second leg outputs ofsaid second induction means modulate at opposite phases of 180 degreesand 0 degrees forming "MOD +" and "MOD -", respectively, relative to acarrier signal supplied to said carrier input of said first inductionmeans; and phase selection means configured to modulate via input ofsaid first and second outputs of said second induction means, said phaseselection means having a F_(t) >1 GHz, and further comprising anemitter, and first and second bases or the equivalent, said first basein circuit with said first output of said second induction means,receiving said "MOD +", said second base in circuit with said secondoutput of said second induction means, receiving said "MOD -"..!.26. Afrequency multiplier circuit utilizing a loosely coupled transformer toadjust, carrier suppression, comprising:a transformer, said transformerfurther comprising first induction means having a carrier input leg andan output leg, second induction means loosely coupled with said firstinduction means, said second induction means having first and second legoutputs, said transformer configured such that said first and second legoutputs of said second induction means modulate at opposite phases of180 degrees and 0 degrees forming "MOD -" and "MOD -", respectively,relative to a carrier signal supplied to said carrier input of saidfirst induction means; first and second capacitors, said first capacitorin parallel circuit with said first and second leg outputs of saidsecond induction means; and phase selection means configured to modulatevia input of said first and second outputs of said second inductionmeans, said phase selection means having a F_(t) >1 GHz, and furthercomprising an emitter, and first and second bases or the equivalent,said first base in circuit with said first output of said secondinduction means, receiving said "MOD +", said second base in circuitwith said second output of said second induction means, receiving said"MOD -".
 27. The method of multiplying a carrier to provide a higherfrequency harmonic, comprising the following steps:a. providing atransformer, said transformer further comprising first induction meanshaving a carrier input leg and an output leg, and second induction meanshaving first and second leg outputs, and a tunable slug or core incommunication with said first and second induction means; b. tuning saidslug or core such that said first and second leg outputs of said secondinduction means modulates at opposite phases of 180 and 0 degrees,forming "MOD +" and "MOD -", respectively, relative a carrier signalsupplied to said carrier input of said first induction means; c.providing phase selection means configured to modulate via input of said. .of said.!. first and second outputs of said second induction means,said phase selection means having a F_(t) >1 GHZ, and further comprisingan emitter, and first and second bases or the equivalent, said firstbase in circuit with said first output of said second inductor,receiving said "MOD +", said second base in circuit with said secondoutput of said second inductor, receiving said "MOD -"; and d.configuring said first base in circuit with said first output leg ofsaid second inductor, receiving said "MOD +", and said second base incircuit with said second output leg of said second inductor, receivingsaid "MOD -", multiplying the carrier to provide a higher frequencyharmonic.
 28. The method of utilizing a loosely coupled transformer toadjust carrier suppression, modulating a carrier signal between a 0degree phase shift and a 180 degree phase shift, and multiplying acarrier to provide a higher frequency harmonic, comprising the followingsteps:a. providing a transformer, said transformer further comprising aninductor having first induction means having a carrier input leg, anoutput leg, and windings, and second induction means having first andsecond leg outputs and windings; b. coupling said windings of said firstand second induction means to a >0.6 and <0.3 coupling coefficient; c.modulating said inductor at opposite phases of 180 degrees and 0degrees, forming "MOD +" and "MOD -", respectively, relative to acarrier signal supplied to said carrier input of said first inductionmeans; d. providing phase selection means configured to modulate viainput of said . .of said.!. first and second outputs of said secondinduction means, said phase selection means having a F_(t) >1 GHZ, andfurther comprising an emitter, and first and second bases or theequivalent, said first base in circuit with said first output of saidsecond inductor, receiving said "MOD +", said second base in circuitwith said second output of said second inductor, receiving said "MOD -".e. configuring said first base in circuit with said first output leg ofsaid second inductor, receiving said "MOD +", and said second base incircuit with said second output leg of said second inductor, receivingsaid "MOD -", multiplying the carrier to provide a higher frequencyharmonic.
 29. A BPSK Modulator circuit having a fixed transformer and avariable tuning capacitor, the fixed transformer and variable tuningcapacitor to adjust carrier suppression in a spread spectrum system,comprising:a transformer, said transformer further comprising firstinduction means having a carrier input leg and an output leg, secondinduction means having first and second leg outputs, a fixedtransformer, and a variable tuning capacitor, the fixed transformer incommunication with said first and second induction means, saidtransformer configured such that said first and second leg outputs ofsaid second induction means modulate at opposite phases of 180 degreesand 0 degrees, forming "MOD +" and "MOD -", respectively, relative to acarrier signal supplied to said carrier input of said first inductionmeans; and first and second phase selection means configured to modulatevia input of said first and second outputs of said second inductionmeans, said first and second phase selection means further comprisingfirst and second load transistors, respectively, each having an emitter,a collector, and a base, said base of said first transistor in circuitwith said first output let of said, second induction means, receivingsaid "MOD +", said base of said second transistor in circuit with saidsecond output of said second induction means, receiving said "MOD -".30. The BPSK modulation System as set forth in claim 3, furtherincluding a fixed transformer and a variable tuning capacitor, saidfixed transformer in communication with said first and second inductionmeans.
 31. The BPSK modulation system as set forth in claim 6, furthercomprising adjustment means for adjusting carrier suppression, saidadjustment means including a fixed transformer and a variable tuningcapacitor, said fixed transformer in communication with said first andsecond induction means.
 32. The method of multiplying a carrier toprovide a higher frequency harmonic, comprising the following steps:a.providing a fixed transformer, said transformer further comprising firstinduction means having a carrier input leg and an output leg, and secondinduction means having first and second leg outputs, and a variabletuning capacitor, said fixed transformer in communication with saidfirst and second induction means; b. tuning fixed transformer andvariable tuning capacitor such that said first and second leg outputs ofsaid second induction means modulates at opposite phases of 180 degreesand 0 degrees, forming "MOD +" and "MOD -", respectively, relative acarrier signal supplied to said carrier input of said first inductionmeans; c. providing phase selection means configured to modulate viainput of said of said first and second outputs of said second inductionmeans, said phase selection means having a F_(t) >1 GHZ and furthercomprising an emitter, and first and second bases or the equivalent,said first base in circuit with said first output of said secondinduction means, receiving said "MOD +", said second base in circuitwith said second output of said second induction means, receiving said"MOD -"; and d. configuring said first base in circuit with said firstoutput leg of said second induction means, receiving said "MOD +", andsaid second base in circuit with said second output leg of said secondinduction means, receiving said "MOD -", multiplying the carrier toprovide a higher frequency harmonic. .Iadd.33. A binary phase shiftkeying (BPSK) modulator comprising:a transformer including a primary anda secondary, said primary having two legs for receiving a carrier signalvia each of two logic gates, respectively and said secondary outputtinga BPSK modulated carrier; and selection means responsive to a BPSK inputsignal, for alternately enabling the two logic gates to pass saidcarrier signal via each of said two legs to said secondary..Iaddend..Iadd.34. A BPSK modulator according to claim 33, wherein thetwo logic gates are biased to operate in a linear region..Iaddend..Iadd.35. A BPSK modulator according to claim 33, wherein thetwo logic gates are transistors each of which is biased to operate in anon-linear region. .Iaddend..Iadd.36. A BPSK modulator according toclaim 33, wherein the two logic gates are selectively enabled to producea harmonic of the carrier signal. .Iaddend..Iadd.37. A BPSK modulatoraccording to claim 36, wherein each of the two logic gates is biased toproduce a predetermined harmonic of said carrier. .Iaddend..Iadd.38. ABPSK modulator according to claim 33, wherein the transformer furthercomprises:means for tuning the transformer to select a predeterminedoutput carrier frequency, including at least one of a capacitor inparallel with the primary and a capacitor in parallel with saidsecondary. .Iaddend..Iadd.39. A BPSK modulator according to claim 36,wherein each of said two logic gates provides amplification of saidcarrier signal. .Iaddend..Iadd.40. A BPSK modulator according to claim33, wherein the transformer is loosely coupled and tuned to produce apredetermined output carrier frequency. .Iaddend..Iadd.41. A BPSKmodulator according to claim 33, further comprising amplification meansfor providing amplification of the enabled gate logic carrier signal..Iaddend..Iadd.42. A BPSK modulator according to claim 33, wherein theselection means is enabled to source or sink current. .Iaddend..Iadd.43.A BPSK modulator according to claim 33, wherein the primary furtherincludes a center tap. .Iaddend..Iadd.44. A BPSK modulator according toclaim 33, wherein a first leg and a second leg of said two legs are 180°out of phase with one another. .Iaddend..Iadd.45. A method formodulating a carrier frequency signal by using a transformer to producea zero degree phase shift and a 180 degree phase shift of the carrierfrequency signal, said method comprising the steps of:selectivelyenabling a zero degree input leg of the transformer in response to afirst binary phase shift keying (BPSK) signal; selectively enabling a180 degree input leg of the transformer in response to a second BPSKsignal; and supplying a carrier signal to the transformer via said zerodegree input leg and said 180 degree input leg, wherein the zero degreeinput leg and the 180 degree input leg are alternately selected by saidfirst and second BPSK signals to produce BPSK modulation of said carrierfrequency signal at an output of the transformer. .Iaddend..Iadd.46. Themethod according to claim 45, wherein the steps of selectively enablingeach include a step of: biasing a selection means into a linear regionof operation. .Iaddend..Iadd.47. The method according to claim 45,wherein each of the steps of selectively enabling each produce aharmonic of the carrier frequency signal. .Iaddend..Iadd.48. The methodaccording to claim 47, wherein the steps of selectively enabling eachinclude a step of:biasing a selection means to produce a predeterminedharmonic. .Iaddend..Iadd.49. The method according to claim 45, furthercomprising the step of: tuning the transformer to a predetermined outputcarrier frequency. .Iaddend..Iadd.50. The method according to claim 49,wherein said step of tuning is performed using at least one of acapacitor on a primary of the transformer and a capacitor on a secondaryof the transformer. .Iaddend..Iadd.51. The method according to claim 45,further comprising the step of: amplifying the carrier frequency signalwithin each of said zero degree input leg and said 180 degree input leg..Iaddend..Iadd.52. The method according to claim 45, further comprisingthe step of: loosely coupling and tuning the transformer to apredetermined output carrier frequency. .Iaddend..Iadd.53. The methodaccording to claim 45, further comprising the step of: amplifying theselectively enabled carrier signal. .Iaddend..Iadd.54. The methodaccording to claim 45, wherein the selection means is enabled to sourceor sink current. .Iaddend..Iadd.55. The method according to claim 45,wherein the zero degree input leg and the 180° input leg are included ina primary of the transformer, said primary having a center tap leg..Iaddend..Iadd.56. The method, according to claim 45, wherein the stepsof selectively enabling each include a step of:biasing a selection meansinto a non-linear region of operation. .Iaddend.